Turbo decoder stopping criterion improvement

Abstract

A stopping criterion improvement for a turbo decoder that does not require division by a variable quantity. The stopping criterion improved upon generates a signal-to-noise ratio based on the mean and variance of soft-output estimates. The decoding process is aborted based on a comparison of the generated signal-to-noise ratio to a predetermined threshold.

1. A turbo decoding system, comprising:
 a decoder module, using an adaptive abort criterion to halt iteration; and  
 executing said adaptive abort criterion by manipulating an abort criterion equation by replacing division by a variable with multiplication by a variable thereby simplifying hardware implementation.  
 
     
     
       2. The system of  claim 1 , wherein the abort criterion is based on the mean and variance of partially decoded extrinsics. 
     
     
       3. The system of  claim 1 , wherein the abort criterion is based on a ratio of the mean and variance of partially decoded extrinsics. 
     
     
       4. An iterative decoder system, comprising:
 a decoder module, for generating estimates of data symbols through an iterative decoding process;  
 a comparator having a comparison algorithm for comparing a derived quality attribute of the generated data symbol estimates to a predetermined threshold said;  
 comparison algorithm being executed by manipulating an abort criterion equation by replacing division by a variable with multiplication by a variable thereby simplifying hardware implementation; and  
 means to abort said decoding based on a comparison result.  
 
     
     
       5. The system of  claim 4 , wherein the quality attribute is based on the mean and variance of the estimates of data symbols. 
     
     
       6. The system of  claim 4 , wherein the quality attribute is based on a ratio of the mean and variance of the estimates of data symbols. 
     
     
       7. The system of  claim 4 , wherein the quality attribute is generated without division by a variable. 
     
     
       8. An abort criterion in iterative decoding, comprising the steps of:
 generating estimates of data symbols;  
 executing a comparison algorithm by manipulating an abort criterion equation by replacing division by a variable with multiplication by a variable thereby simplifying hardware implementation;  
 comparing the quality attribute to a predetermined threshold; and  
 aborting the turbo decoding based on a comparison result.  
 
     
     
       9. The method of  claim 8 , wherein the quality attribute is based on the mean and variance of the estimates of data symbols. 
     
     
       10. The method of  claim 8 , wherein the step of comparing is implemented without division by a variable. 
     
     
       11. An abort criterion in iterative decoding, comprising the steps of:
 (a.) generating estimates of data symbols after an iteration substep;  
 (b.) measuring the mean of the estimates;  
 (c.) measuring the variance of the estimates;  
 (d.) generating a quality attribute based on the mean and the variance;  
 (e.) comparing the quality attribute to a predetermined threshold; and  
 (f.) aborting the turbo decoding based on a comparison result; wherein the steps (b), (c), (d), and (e) are implemented without division by a variable.  
 
     
     
       12. The method of  claim 11 , wherein the quality attribute is based on a ratio of the mean and the variance of the estimates. 
     
     
       13. An iterative decoder system for a recursive systematic encoder, comprising:
 a decoder module, wherein estimates of data symbols are generated through an iterative decoding process;  
 a comparison algorithm for comparing a quality attribute of the generated data symbol estimates to a predetermined threshold;  
 wherein the quality attribute is based on the mean and the variance of the estimates;  
 wherein decoding is aborted based on the result of said comparison; and  
 wherein the mean and variance for the estimates and the comparison algorithm are implemented without division by a variable.  
 
     
     
       14. The system of  claim 13 , wherein the quality attribute is based on a ratio of the mean and variance of the estimates.